Senator Kamala Harris (D-CA) sent a letter late last week to JPMorgan Chase CEO Jamie Dimon that lambasted him for the bank’s recent move to reinstate forced arbitration on its credit cards.

“We urge JPMorgan Chase to withdraw the forced arbitration clause in its credit card agreements,” she said in a letter cosigned by Senator Richard Blumenthal (D-CT).

As Fast Company first reported, the bank is quietly reintroducing a clause in its credit card customers’ terms of service that waves their rights to sue Chase in a court of law. Under these new rules, cardholders are also unable to join class action lawsuits against the bank. Ten years ago, Chase, along with a bunch of other top U.S. banks, stopped making customers sign forced arbitrations clauses following a lawsuit. Now that the dust has settled, it seems Chase wants to bring the practice back into vogue.

Harris notes in her letter that the timing of this new clause is curious, especially given protests at Google over employee contracts with similar arbitration clauses. The letter then asks for answers about why the bank decided to put the practice back into use. The senators asked for a response by Friday, June 28.

For now, the only thing Chase customers can do is voluntarily opt out. To do that, they must send a letter via snail mail, making the process even more onerous. I asked Chase for comment about this latest development and will update if I hear back.